Hi YAG...yes you're absolutely right. Love IS painful but it's only painful because of a lack of inner strength. When you feel good about yourself, then you want to give to the other instead of taking. For example, jealousy is about 'taking', not giving.
A good sense of self = giving.
A poor sense of self = taking.
Make no mistake, we all have needs so of course we take, but the difference is, we don't suck emotional energy from the other to top up what in fact is our responsibility. In other words, if you're needy, then you place unrealistic expectations on your partner: you demand that s/he gives you what you can't give to yourself. Feeling good about yourself has to come from within you. It's unhealthy and unrealistic to put that responsibility onto the other. Jealousy is about insecurity and insecurity is about not feeling sure of where you're placed or who you are. Insecurity is a lack of certainty, both metaphorically and literally.
Having said this, you may have inner strength but the person you love doesn't. THIS will definitely create pain. Both parties need inner strength to remove game playing which leads to pain. YES love does take over, it's about vulnerability but this is needed in order to reach freedom and happiness.